Foam construction and mattress or pillow provided therewith

ABSTRACT

Foam construction ( 1 ) for use in a mattress or pillow, that comprises a base ( 2 ) extending in a longitudinal direction (L) that is made of a flexible synthetic foam, whereby this base ( 2 ) comprises two arms ( 4 ) extending in the longitudinal direction that are connected by a breathable bridge ( 5 ) that extends in the said longitudinal direction (L).

The present invention relates to a foam construction and a mattress provided therewith.

More specifically, the invention concerns a foam construction of flexible synthetic foam that is very suitable for forming the base of a mattress.

A very important property of a mattress, that determines the comfort of a mattress, is the extent to which heat and perspiration moisture can be removed from the surface on which the user lies, so that a mattress does not feel too warm and clammy while sleeping.

It is especially important for restful REM sleep to have a relatively low body temperature from the start of the sleep, i.e. good heat removal.

As is known many mattresses are made from relatively soft, flexible synthetic foam, such as latex or PUR on account of the relatively low cost and the easy processing of them.

These synthetic foams exist in a normal elastic variant and a viscoelastic variant.

However, these foams have the disadvantage that they have relatively small pores in which air is trapped, such that there is only a slow circulation of air, such that the heat removal and removal of perspiration moisture from a sleeping person is often not optimum. As a result optimum sleeping comfort is difficult to achieve, and mould and bacterial growth can occur in the mattress.

Large open cell foams are indeed known, but they may not be thicker than 1 to 2 cm in a mattress so that they do not prevent air circulation. However, with such a low thickness these foams provide insufficient elasticity to make a good mattress.

A special class of such foams for mattresses are the viscoelastic foams.

They have very attractive properties regarding the suspension and support of the body of the user, because they can absorb large quantities of energy and only release it again slowly, such that the body of the user is well supported over a large area. As a result they are much used in hospitals for example to prevent bedsores, but also for home use on account of their comfortable supporting nature.

However, these foams have the disadvantage that the speed with which the air is allowed through is even slower than with the above-mentioned elastic foams, because they have a relatively high fraction of closed pores.

As a result they feel very warm and the user can feel uncomfortable as a result of the poor moisture removal, and for bedridden people can even lead to other types of skin problems.

With spring mattresses more air circulation is of course possible around the springs, but the exchange of air with the surface on which the user lies is impeded by the necessary presence of a covering over the springs.

In brief, with existing mattress constructions good ventilation of the surface on which the user lies is not possible, so that perspiration moisture and warm air accumulate in the mattress, and sleep can be interrupted or is less restful.

The purpose of the present invention is to provide a solution to the aforementioned and other disadvantages by providing a mattress that is provided with two or more foam constructions placed next to one another sideways, that each comprise a base extending in a longitudinal direction whereby this base is made of a flexible synthetic foam and this base comprises two arms extending in the longitudinal direction, that are connected, preferably at their ends, by a breathable bridge that extends in the said longitudinal direction, whereby the bridge is oriented upwards.

For completeness it is noted that the longitudinal direction is generally, but not necessarily, the largest distance over which a said foam structure extends, but is the direction in which the cross-section of the base does not or not significantly change.

For clarity it is emphasised that the base as a whole, the arms, and the bridge extend in the longitudinal direction, i.e. these components are present in an unchanging mutual configuration over a certain distance in the longitudinal direction.

Hereby the bridge can be made of foam, but the bridge can also be made of other materials, such as a breathable textile or a knitted 3D fabric.

Normally speaking the bridge is a flat structure that extends in the longitudinal direction and in a direction perpendicular to it in order to bridge the entire space between the arms.

In a preferred embodiment the bridge is provided with passages.

In a further preferred embodiment the base is not provided with passages.

These passages guarantee sufficient breathability of the bridge.

Thanks to the breathable bridge such a mattress provides very good air circulation, because perspiration moisture from the user can be removed well from the surface on which the user lies.

This proceeds via induced ventilation. This means that due to the heating of the air in the mattress close to the body of a sleeping person, an upward airflow comes into being via the breathable bridge.

Fresh air comes into the mattress sideways, via the space between the arms of the foam constructions, and this air is again heated so that permanent good ventilation with fresh air, and the removal of warm air with perspiration moisture therein, is obtained.

Thanks to the arms and the bridge, there are two different types of foam components that a mattress designer can adapt to obtain the desired body-supporting properties, so that the foam construction provides great flexibility for a mattress designer.

In a preferred embodiment the bridge is made of viscoelastic foam.

As a result the above-mentioned attractive properties of viscoelastic foam can be combined with good ventilation properties obtained by the specific foam construction and mattress construction.

In a further preferred embodiment the base is made of non-viscoelastic foam. This enables a relatively sturdy, i.e. not too soft, foam construction to be made with a low cost and a low weight.

In another further preferred embodiment the bridge is made of a strip of foam that is provided with cuts, whereby the base is arranged to exert a tensile force on the bridge such that the cuts are pulled open, and thereby form the said passages.

This gives the entire foam construction a better elastic character. Moreover, this enables relatively small cuts to be made but with relatively large passages obtained, so that there is little or no material loss. Also, such a bridge under tension ensures that the passages are not pushed closed by a deformation of the bridge, as can occur when a person lies on the mattress.

In a further preferred embodiment the cuts, when the bridge is in an unstretched state, are linear incisions.

Hereby an incision means that no material is removed when it is made, such that the cut surfaces of a volume with an incision fit precisely together, while a cut comprises supplementary openings that are made by removing material and where the cut surfaces of a cut volume do not fit together precisely.

By making cuts in the form of an incision, it results in no material loss such that no foam is lost and the cuts can also be made with simple tools.

In a preferred embodiment the base comprises precisely two arms that are parallel to one another, that are at a distance from one another, and which extend over the length, and preferably over the entire length, of the foam construction, such that a channel is formed between the arms that extends in the said longitudinal direction.

In a preferred embodiment, the base, in a cross-section transverse to the longitudinal direction, is U-shaped or V-shaped with a back and two arms. The back hereby connects the two arms at the other side than the bridge, so that the foam construction is tubular.

Compared to a full foam layer, such a tubular construction is lighter and uses less material. A tube is also open at its ends such that fresh air can freely flow into the mattress.

In another preferred embodiment the base is formed by a strip or sheet of foam that is bent into a V-shape or U-shape, and is thereby under a bending stress and which, due to its elasticity, in other words due to this bending stress, can exert a tensile force on the bridge.

It goes without saying that the bridge hereby exerts a tension on the V-shaped or U-shaped bent strip of foam so that it remains V-shaped or U-shaped.

The width and dimensions of the bridge and the spring characteristics of the strip of foam and the bridge hereby together determine the shape of the foam structure.

This is an easy way to make such a foam construction.

In a preferred embodiment the foam constructions are glued or welded together sideways. This means that an arm of a foam construction is glued or welded to one of an adjacent foam construction.

This has the advantage that a downward load, that results in a sideways bulging of the arms, is transmitted to adjacent foam constructions, such that such a combination of foam constructions presents much more sturdiness than a separate foam construction, and has a very good elastic behaviour with a relatively small quantity of foam.

Alternatively they can glued be individually, arranged side-by-side onto a bottom plate, or if applicable to a top plate of very breathable material.

In a further preferred embodiment the said longitudinal direction of the foam constructions is transverse to the direction from the head end to the foot end of the mattress. This has the advantage that different zones of the mattress can be constructed with different properties in order to be better suited to the different zones of the human body.

In a further preferred embodiment the mattress is provided with means to actively impose an airflow in the space between the arms of at least one of the foam constructions.

On account of the foam constructions placed next to one another, which as it were form individual channels, a mattress provided with the foam constructions is extremely suitable for connecting some or all channels to an air pump or air extraction system, in order to, if necessary, further improve the air circulation and the moisture removal, but also in this way to provide the mattress with heating or cooling.

The invention also comprises a cushion, i.e. a pillow, lounger cushion or hassock, that is provided with two or more foam constructions placed next to one another sideways as described above, whereby preferably the bridge is oriented upwards, i.e. towards the side that is intended to come in contact with a person.

The invention further comprises the foam construction described above for use in a mattress or pillow, hassock or lounger cushion.

With the intention of better showing the characteristics of the invention, a preferred embodiment of a foam construction and a mattress according to the invention is described hereinafter by way of an example, without any limiting nature, with reference to the accompanying drawings, wherein:

FIG. 1 schematically shows a perspective view of a foam construction according to the invention;

FIG. 2 schematically shows a perspective view of a mattress core of a mattress according to the invention;

FIG. 3 shows the part of FIG. 2 designated by F3 on a larger scale;

FIGS. 4 and 5 show successive steps in the manufacture of the foam construction of FIG. 1;

FIG. 6 schematically shows a perspective view of a mattress core of an alternative mattress according to the invention;

and FIG. 7 shows the part of FIG. 6 designated by F7 on a larger scale.

The foam construction 1 shown in FIG. 1 is tubular and extends in the longitudinal direction indicated by L.

The foam construction 1 has a width B, in this example but not necessarily of 10 cm and a high H, in this example but not necessarily of 15 cm.

The foam construction 1 consists of two components connected together by means of glueing, i.e. a bent U-shaped base 2 with a back 3 and two arms 4 and a straight strip of foam that forms a bridge 5 between the arms 4.

The base 2 is made of a strip of flexible non-viscoelastic PUR foam, which in this example but not necessarily has a thickness DI of 25 mm and which is bent into a U-shape so that the arms 4 exert a slight tensile force on the bridge 5 oriented towards the outside.

The bridge 5 is made of viscoelastic foam, in this example with a thickness D2 of 20 mm and is provided with a regular pattern of passages 6 between the top of the bridge 5 and the space 7 between the arms.

The passages 6 are rhombic and in the longitudinal direction L form running discontinuous lines 8 that are staggered with respect to one another.

The bridge 5 is kept somewhat under tension by the arms 4 of the base, such that the passages 6 are pulled open, which is the case to a greater extent near the centre than closer to the arms 4. The bridge 5 hereby prevents the arms 4 from springing outwards, but keeps them in the desired position.

As shown in FIGS. 2 and 3 a mattress can easily be manufactured from the foam constructions 1 described above.

It is hereby noted that only a mattress core 9 is shown in FIGS. 2 and 3. In order to make a mattress from this mattress core, it is sufficient to provide a textile cover to enclose this mattress core 9. Optionally, supplementary top or bottom layers can be provided within the said cover. It is hereby necessary for the sides to remain open enough in order to enable a good inflow of air.

The mattress core 9 of FIGS. 2 and 3 essentially consists of a number, in this example twenty, of the foam constructions 1 described above that are all manufactured or cut to the same length L, corresponding to the width of the mattress core 9.

The foam constructions 1 are placed next to one another sideways, with the bridges 5 oriented upwards and glued together at the location of the arms 4 located next to one another on a bottom plate 10 of flexible foam.

The longitudinal direction L of the individual foam constructions 1 hereby runs in the crosswise direction of the mattress core, thus in the direction perpendicular to a line from the head end 11 to the foot end 12.

Air can now move freely between the surface against which a user lies and the environment, through the passages 6 in the bridge 5 and via the channels formed by the space 7 between the arms 4 of each foam construction 1.

As a result of the body heat of the user an airflow can be induced that is upwards at the location of the passages 6, so that fresh surrounding air is permanently supplied from the environment, and such that it prevents a mattress formed from the mattress core 9 feeling too warm.

The perspiration moisture of a person who sleeps on such a mattress is removed with this air to the side of the mattress and from there to the environment.

This effect is amplified by movements of the user. The mattress can also be provided with, or connected to, a device for blowing or extracting air. Such a device can be connected at a side of the mattress to each or a number of the spaces 7 between the arms 4 of individual foam constructions 1.

It is of course relatively easy, with the method shown for composing the mattress core, to obtain different elastic and viscoelastic behaviour in different zones of a mattress by adapting the thickness and type of the foam layers from which the base 2 and the bridge 4 are made in a foam construction 1 used in a zone concerned.

A foam construction 1, as shown above, can be manufactured as follows.

A strip of viscoelastic foam intended to form the bridge 5 is provided with a number of straight lines 8 with cuts, whereby these lines 8 extend in the longitudinal direction L of the foam construction 1 to be manufactured.

The cuts are made in the form of straight incisions 13, which means that no material is removed when making them.

Each line 8 with incisions 13 comprises alternating incisions 13 and non-cut sections, whereby the incisions 13 are made with a regular pitch S. The incisions 13 of lines 8 located next to one another are mutually staggered over a distance of half the pitch S, so that a regular pattern of incisions 13 is obtained.

The incisions 13 can be made in many different ways. An easy way is to use a rotating disk with a number of blades whereby the strip of viscoelastic foam is guided between this rotating disk and a cutting table.

A strip of foam with incisions 13 thus obtained is shown in the top part of FIG. 3.

A straight strip of foam for the base 2 is then bent into a horseshoe shape, as shown in the bottom part of FIG. 3. The distance A between the sides 14 bent towards one another is approximately 15 mm.

A layer of adhesive 15 is applied to the sides 14 bent towards one another, which after bending form the top of the horseshoe shape. This can be on a complete side 14 or only on a part thereof, as shown in FIG. 3.

Then the strip of foam for the bridge 5 is placed on the sides 14 bent towards one another of the strip of foam for the base 2 to until the adhesive 15 has set sufficiently. This is shown in FIG. 4.

If no forces are now exerted on the foam construction thus formed, the arms 4 of the base 2 will bend towards the outside and thereby exert a tensile force on the bridge 5 such that the incisions 13 are pulled open into rhombic passages 6, as shown in FIG. 1, and such that the arms 4 are practically or completely parallel and a foam construction 1 as shown in FIG. 1 is formed.

Such a foam construction can be manufactured with a specific required length L, but can also be manufactured almost endlessly with an unspecified length, and then cut to the desired length L.

De alternative mattress core 9 shown in FIGS. 6 and 7 differs from the mattress core 9 described above, because it is composed of a large number of short foam constructions 1, in this case with a length L of approximately 12 cm.

They are placed next to one another such that a number of foam constructions 1, in this example seven, are in line with one another and form a row 16 and a number, in this example twenty, of such rows 16 are placed next to one another sideways so that a surface is formed to serve as a mattress core 9.

The mutual distance A between the foam structures 1 in a row 16 is typically a few millimetres.

Such a mattress core 9 has the advantage that the good air circulation of the mattress core 9 described earlier is preserved, while nevertheless a local deformation is not passed on to adjacent foam constructions 1 in a row 16, so that the elastic behaviour of the total mattress core 9 is better suited to accommodate highly different local forces with highly different local extents of deformation.

Such mattress cores 9 can be manufactured in different ways.

A possibility is to first manufacture a mattress core 9 according to FIG. 2, and then to make incisions perpendicular to the longitudinal direction L of the foam constructions 1. As a result, the bottom plate 10 can either be omitted, or cut through as well and sacrificed, after which a new bottom plate 10 can be provided as in FIG. 6.

Another possibility is to first make relatively long foam constructions 1 as in FIG. 1, and then to saw them to the desired length L, and to put them together into a mattress core 9.

Of course, short individual foam constructions 1 according to the invention can also be made from short strips of foam for the base 2 and for the bridge, but this has the disadvantage that it requires a relatively large amount of work.

The present invention is by no means limited to the embodiments described as an example and shown in the drawings, but a foam construction and mattress according to the invention can be realised in all kinds of forms and dimensions, without departing from the scope of the invention. 

1. A foam construction (1) for use in a mattress or pillow, that comprises a base (2) extending in a longitudinal direction (L) that is made of a flexible synthetic foam, whereby this base (2) comprises two arms (4) extending in the longitudinal direction that are connected by a breathable bridge (5) that extends in the said longitudinal direction (L).
 2. The foam construction according to claim 1, characterised in that the base (2), in a cross-section transverse to the longitudinal direction (L), is V-shaped or U-shaped with a back (3) and the two twee arms (4), so that the foam construction (1) is formed as a tube extending in the longitudinal direction (L), whereby the bottom of the tube is formed by the back (3), the top of the tube is formed by the bridge (5) and the sides of the tube are formed by the arms (4).
 3. The foam construction according to claim 1, characterised in that the base (2) is formed from a strip of foam that is bent into a V-shape or U-shape and exerts a tensile force on the bridge (5) due to its elasticity.
 4. The foam construction according to claim 1, characterised in that the bridge (5) is provided with passages (6) that run from the space (7) between the arms (4) to the surface of the bridge (5) turned away from the base (2).
 5. The foam construction according to claim 4, characterised in that the bridge (5) is made of a strip of foam that is provided with cuts (13), whereby de base (2) is arranged to exert a tensile force on the bridge (5) such that the cuts (13) are pulled open and thereby form the said passages (6).
 6. The foam construction according to claim 5, characterised in that, when the bridge (5) is in an unstretched state, the bridge (5) is provided with two or more lines (8) with cuts (13), whereby the lines (8) essentially extend in the said longitudinal direction (L) and whereby the lines (8) are each defined by a succession of cuts (13) with a regular pitch (S), whereby the lines (8) extend parallel to one another and whereby the positions of the cuts (13) of adjacent lines (8) are staggered.
 7. The foam construction according to claim 6, characterised in that the positions of the cuts (13) of adjacent lines (8) are staggered over a distance that corresponds to a half pitch (S) of the cuts (13).
 8. The foam construction according to claim 6, characterised in that the cuts (13), when the bridge (5) is in an unstretched state, are straight and extend in the direction of the lines (8), so that approximately rhombic passages (6) occur in the stretched state of the bridge (5).
 9. The foam construction according to claim 1, characterised in that the base (2) comprises precisely two arms (4) that run parallel to one another, that are at a distance from one another and which extend in the longitudinal direction (L) of the foam construction (1), such that a channel is formed between the arms (4) that extends in the said longitudinal direction (L).
 10. The foam construction according to claim 1, characterised in that the foam construction (1) is tubular and extends in the said longitudinal direction (L).
 11. The foam construction according to claim 1, characterised in that the bridge (5) is made of a viscoelastic foam.
 12. A mattress that is provided with two or more foam constructions (1) according to claim 1 placed next to one another sideways, whereby the bridge (5) is oriented upwards.
 13. A mattress that is provided with two or more foam constructions according to claim 1 that are placed next to one another in the longitudinal direction of the foam constructions.
 14. The mattress according to claim 12, characterised in that the foam constructions (1) placed next to one another extend over the entire or practically entire surface of the mattress.
 15. The mattress according to claim 13, characterised in—that the foam constructions (1) that are placed next to one another sideways are glued or welded together.
 16. The mattress according to claim 13, characterised in that the said longitudinal direction (L) is transverse to the direction from the head end (11) to the foot end (12) of the mattress.
 17. The mattress according to claim 13, characterised in that the mattress is provided with means to impose an airflow in the space between the arms (4) of at least one of the foam constructions (1) or is equipped to be connected to such means.
 18. A pillow that is provided with one or more foam constructions (1) according to claim 1, whereby the bridge (5) is oriented upwards.
 19. The pillow according to claim 18, characterised in that the foam constructions (1) are connected together sideways and are preferably glued together. 